5522 results about "Metal catalyst" patented technology

Single-walled carbon nanotubes have been synthesized by the catalytic decomposition of both carbon monoxide and ethylene over a supported metal catalyst known to produce larger multi-walled nanotubes. Under certain conditions, there is no termination of nanotube growth, and production appears to be limited only by the diffusion of reactant gas through the product nanotube mat that covers the catalyst The present invention concerns a catalyst-substrate system which promotes the growth of nanotubes that are predominantly single-walled tubes in a specific size range, rather than the large irregular-sized multi-walled carbon fibrils that are known to grow from supported catalysts. With development of the supported catalyst system to provide an effective means for production of single-wall nanotubes, and further development of the catalyst geometry to overcome the diffusion limitation, the present invention will allow bulk catalytic production of predominantly single-wall carbon nanotubes from metal catalysts located on a catalyst supporting surface.

A single-crystal graphene sheet includes a polycyclic aromatic molecule wherein a plurality of carbon atoms are covalently bound to each other, the single-crystal graphene sheet comprising between about 1 layer to about 300 layers; and wherein a peak ratio of a Raman D band intensity to a Raman G band intensity is equal to or less than 0.2. Also described is a method for preparing a single-crystal graphene sheet, the method includes forming a catalyst layer, which includes a single-crystal graphitizing metal catalyst sheet; disposing a carbonaceous material on the catalyst layer; and heat-treating the catalyst layer and the carbonaceous material in at least one of an inert atmosphere and a reducing atmosphere. Also described is a transparent electrode including a single-crystal graphene sheet.

The slag oil hydrodemetallizing catalyst contains a kind of double-peak hole alumina carrier and supported Mo and / or W and Ni and / or Co metal components. The double-peak hole alumina carrier has pore volume of 0.8-1.6 ml / g, specific surface area 150-350 sq m / g, pore volume fraction of 10-30 nm size holes in 40-90 % and pore volume fraction of 100-2000 nm size holes in 10-60 %, and is prepared through mixing alumina hydrate and ammonium aluminum carbonate, forming and roasting. The slag oil hydrodemetallizing catalyst has simple preparation process and high hydrodemetallizing performance.

The present invention pertains to catalyst systems for nitrogen oxide, carbon monoxide, hydrocarbon, and sulfur reactions that are free or substantially free of platinum group metals. The catalyst system of the present invention comprise a substrate and a washcoat, wherein the washcoat comprises at least one oxide solid, wherein the oxide solid comprises one or more selected from the group consisting of a carrier material oxide, a catalyst, and mixtures thereof. The catalyst system may optionally have an overcoat, wherein the overcoat comprises at least one oxide solid, wherein the oxide solid comprises one or more selected from the group consisting of a carrier material oxide, a catalyst, and mixtures thereof. The catalyst comprises one or more selected from the group consisting of a ZPGM transition metal catalyst, a mixed metal oxide catalyst, a zeolite catalysts, or mixtures thereof.

This invention provides a process for hydrotreating hydrocarbon resins, which process comprises contacting a feedstock comprising a hydrocarbon resin or rosin, under suitable hydrotreating conditions, with a bulk multimetallic catalyst comprised of at least one Group VIII non-noble metal and at least two Group VIB metals and wherein the ratio of Group VIB metal to Group VIII non-noble metal is from about 10:1 to about 1:10. The process accord invention can achieve increased hydrocarbon resin productivity through increase in throughput volumes and effective catalyst lifetimes. The process of the invention is desirably practiced with a bulk catalyst consisting of only the combination of the metal species with the active metal components. The absence of carrier substrates largely removes the possibility of halogen accumulation on substrate surfaces that, in turn, can acidify metal catalysts such that additional, progressive cracking of the hydrocarbon resin molecules occurs.

The present invention pertains to catalyst systems for nitrogen oxide, carbon monoxide, hydrocarbon, and sulfur reactions that are free or substantially free of platinum group metals. The catalyst system of the present invention comprise a substrate and a washcoat, wherein the washcoat comprises at least one oxide solid, wherein the oxide solid comprises one or more selected from the group consisting of a carrier material oxide, a catalyst, and mixtures thereof. The catalyst system may optionally have an overcoat, wherein the overcoat comprises at least one oxide solid, wherein the oxide solid comprises one or more selected from the group consisting of a carrier material oxide, a catalyst, and mixtures thereof. The catalyst comprises one or more selected from the group consisting of a ZPGM transition metal catalyst, a mixed metal oxide catalyst, a zeolite catalysts, or mixtures thereof.

A gas-phase method for producing high yields of single-wall carbon nanotubes with high purity and homogeneity is disclosed. The method involves using preformed metal catalyst clusters to initiate and grow single-wall carbon nanotubes. In one embodiment, multi-metallic catalyst precursors are used to facilitate the metal catalyst cluster formation. The catalyst clusters are grown to the desired size before mixing with a carbon-containing feedstock at a temperature and pressure sufficient to initiate and form single-wall carbon nanotubes. The method also involves using small fullerenes and preformed sections of single-wall carbon nanotubes, either derivatized or underivatized, as seed molecules for expediting the growth and increasing the yield of single-wall carbon nanotubes. The multi-metallic catalyst precursors and the seed molecules may be introduced into the reactor by means of a supercritical fluid. In addition the seed molecules may be introduced into the reactor via an aerosol or smoke.

A cold start catalyst is disclosed. The cold start catalyst comprises a zeolite catalyst and a supported platinum group metal catalyst. The zeolite catalyst comprises a base metal, a noble metal, and a zeolite. The supported platinum group metal catalyst comprises one or more platinum group metals and one or more inorganic oxide carriers. The invention also includes an exhaust system comprising the cold start catalyst. The cold start catalyst and the process result in improved NOx storage and NOx conversion, improved hydrocarbon storage and conversion, and improved CO oxidation through the cold start period.

The present invention relates to a process for the purification of single-wall carbon nanotubes and the purified single-wall carbon nanotube material. Known methods of single-wall carbon nanotube production result in a single-wall carbon nanotube product that contains single-wall carbon nanotubes in addition to impurities including residual metal catalyst particles and amounts of small amorphous carbon sheets that surround the catalyst particles and appear on the sides of the single-wall carbon nanotubes and "ropes" of single-wall carbon nanotubes. The purification process removes the extraneous carbon as well as metal-containing residual catalyst particles. The process employs steps including a gas-phase oxidation of the amorphous carbon and subsequent liquid-phase reaction of a halogen-containing acid with the metal-containing species. Optionally, the single-wall carbon nanotube material may be annealed dry or in the presence of moisture. The present invention provides a scalable means for producing high-purity single-wall carbon nanotube material.

A method is described for catalyst-induced growth of carbon nanotubes, nanofibers, and other nanostructures on the tips of nanowires, cantilevers, conductive micro / nanometer structures, wafers and the like. The method can be used for production of carbon nanotube-anchored cantilevers that can significantly improve the performance of scaning probe microscopy (AFM, EFM etc). The invention can also be used in many other processes of micro and / or nanofabrication with carbon nanotubes / fibers. Key elements of this invention include: (1) Proper selection of a metal catalyst and programmable pulsed electrolytic deposition of the desired specific catalyst precisely at the tip of a substrate, (2) Catalyst-induced growth of carbon nanotubes / fibers at the catalyst-deposited tips, (3) Control of carbon nanotube / fiber growth pattern by manipulation of tip shape and growth conditions, and (4) Automation for mass production.

A catalyzed diesel particulate filter (CDPF) and a method for filtering particulates from diesel engine exhaust are provided, where the catalyzed diesel particulate filter includes a substrate and a catalyst composition, where the catalyst composition contains at least one first component, at least one second component, and at least one third component, where the first component is at least one first component selected from the group consisting of cerium and a lanthanide and mixtures thereof, the at least one second component is selected from the group consisting of cobalt, copper, manganese and mixtures thereof; and the third component comprises strontium, where the first component, the second component, and the third component are in an oxide form after calcination. The catalyst on the catalyzed diesel particulate filter lowers the temperature at which particulates are removed from the CDPF by oxidizing the particulates on the filter. The catalyzed diesel particulate filter may also include a washcoat. Washcoats prepared from colloidal aluminum oxide may have higher surface areas and pore volumes loadings than washcoats containing aluminum oxide prepared from aluminum nitrate.